The invention relates generally to methods and systems for monitoring router reconfigurations and more particularly to reducing the likelihood of faulty network conditions as a result of router reconfigurations.
Within a large enterprise, such as a university or a major corporation, there may be a large number and a variety of types of devices that are supported by a segmented network. Network devices include personal computers, Internet Protocol (IP) telephones, servers, and printers. The segmentation of the network may be referred to as a Wide Area Network (WAN) or a Local Area Network (LAN) that is divided into subnetworks. Each subnetwork of a WAN or a LAN may be assigned one or more routers. Routers allow a WAN or LAN to be divided, so as to maintain data security for different divisions of an enterprise, while still enabling division-to-division intercommunications.
A router is a network component having at least two Network Interface Cards (NICs) that are compatible with a particular protocol, such as Internet Protocol (IP). Upon receiving a data packet, a router will determine the next hop the data packet must take in order to reach the destination device indicated by the destination address of the packet. Packets may be forwarded from one router to the next until the final router which supports the destination device is reached.
A router maintains a router table of addresses, such as IP addresses. Within the router table, each IP address is associated with a network interface that is to be used in forwarding packets having that address. However, routing loops occur when router tables are misconfigured. When another router or another router-to-router link is added to a network, router tables must be updated. The reconfiguration of the table may be performed manually. When a router table is inadvertently misconfigured, a loop in the network may result, so that a data packet will be continuously recycled between two or more routers. The data packet will continue to propagate through the network until a Time-to-Live (TTL) counter is exceeded, at least in the case of IP data packets. The continuous recycling of the misrouted packets can significantly reduce a data network's bandwidth. In some circumstances, the bandwidth may be so taxed as to cause a switch or a router to “crash.” For some enterprises, the network is used to carry Telephony-over-LAN (ToL) voice information, so that a routing loop may cause disruption to the telephone service of the enterprise.
Routers of an enterprise routinely update each other, so that a misconfiguration of one router may be propagated to other routers in the network. As a consequence, reversing the changes throughout the network may take a significant period of time.
What is needed is a method and system for reducing the susceptibility of a network to faulty routing conditions as a result of router reconfigurations.